1. Field of the invention
The invention is in the field of installing a cable in a tubular cable duct. More particularly, the invention relates to a new installation method and device.
2. Prior art
In the case of the cable installation methods hitherto known, two types can in general be distinguished. A first type is distinguished in that a cable is pulled into the duct by exerting a pulling force on the foremost end of the cable. Such a method in which this is done with the aid of a winching wire attached to the foremost cable end is known, for example, from reference [1]. A method in which this is done with the aid of a pulling plug which is attached to the cable end and which is energised in the duct by means of compressed air is known, for example, from reference [2]. A disadvantage of a method of this type is that, as a consequence of the tension in the cable, the pulling force needed increases exponentially in the bends or undulations in the duct which are virtually always present. The second type of methods is distinguished in that the pulling force is as far as possible distributed over the entire length of the cable in the duct. In a method of said second type known from reference [3] , this is achieved with the aid of a powerful air stream which is blown along the cable in the duct. Such a distributed pulling force is, as is further also known from references [4] and [5], possibly also supplemented by means of a locally exerted pushing force if the cable to be installed has sufficient stiffness for this purpose. Although very acceptable cable lengths can be installed in one piece by means of a method of the second type, the installation speed remains limited, however, by the nature of the method.